The present invention relates to a golf club head, more particularly to an iron-type golf club head capable of improving the flying distance and directionality of a ball hit by an average golfer.
In general, an iron-type golf club head is designed such that, when a ball is hit at a suitable position such as the sweet spot or the center of the club face, the flying distance of the ball becomes maximum. However, it is difficult For the average golfers to hit a ball at such a suitable position every time. Therefore, in the case of the average golfers, there is a tendency that the flying distance varies wide.
In the circumstances described above, for example, in the Japanese Patent Application Publication Nos. H9-253248 and H10-295861, an iron-type golf club head in which the position of the center of gravity of the club head is lowered has been proposed. Such a club head accordingly has the sweet spot at a lower position on the club face.
In general, an iron-type golf club has many opportunities to hit a ball lying on lawn, therefore, the ball hitting position tends to become in a sole-side region of the club face. Accordingly, in the case of the above-mentioned club head, the actual ball hitting position tends to coincide with the sweet spot. This helps to improve the flying distance.
In the case of a golf club head whose center of gravity is further lowered, chances of hitting a ball on the upper side of the sweet spot become high.
If a ball is hit on the upper side of the sweet spot, the club head is rotated by a small angle so as to increase the loft angle, and the launch angle of the ball is increased accordingly. Thereby, due to the gear effect, the excessive backspin of the ball is prevented. Thus, in this respect too, the club head having the lowered center of gravity is advantageous to increasing the flying distance.
In recent years, on the other hand, an iron-type golf club head constructed to have a large moment of inertia has been proposed. In the Japanese Patent Application Publication No. 2014-410, such a club head is disclosed, wherein the moment of inertia about the Y-axis (vertical axis) extending through the center of gravity of the club head is increased.
In the case of the club head increased in the moment of inertia, even if the ball hitting position is off-centered toward the toe or heel from the sweet spot of the club face, the club head is hard to be rotated around the vertical axis at impact. Thus, such a club head having a large moment of inertia can improve the directionality of the ball hit by an average golfer.